1. Field of the Invention
The present disclosure relates to a fuel cell.
2. Discussion of the Background
For example, a solid polymer electrolyte fuel cell serves as a generation unit cell, in which an electrolyte membrane-electrode assembly (MEA) is sandwiched between a pair of separators, the electrolyte membrane-electrode assembly being formed by disposing an anode electrode and a cathode electrode at both sides of a solid polymer electrolyte membrane formed of a polymer ion exchange membrane. In general, a plurality of generation cells are stacked to form a fuel cell stack, which is incorporated, for example, in a fuel cell vehicle to be used as an in-vehicle fuel cell system.
In a fuel cell, what is called an internal manifold is often formed in order to supply a fuel gas and an oxidant gas as a reactant gas to the anode electrode and the cathode electrode, respectively, in each of the stacked generation cells.
The internal manifold is provided with reactant gas communication holes (a fuel gas communication hole and an oxidant gas communication hole) and a cooling medium communication hole which are provided through the generation cells in the stacking direction. The reactant gas communication hole communicates with reactant gas passages (a fuel gas passage and an oxidant gas passage) for supplying a reactant gas along an electrode surface, and the cooling medium communication hole communicates with a cooling medium passage for supplying a cooling medium along an electrode surface between separators.
For example, a unit cell for a fuel cell, disclosed in Japanese Unexamined Patent Application Publication No. 2006-331783 includes a membrane-electrode assembly 1 which generates power with supplied operating gas, a holding member 2 which holds the membrane-electrode assembly 1 at the periphery, and an anode separator 3 and a cathode separator 4 which sandwich the membrane-electrode assembly 1 and the holding member 2 as illustrated in FIG. 10.
A sealing member 5a is interposed between the anode separator 3, the cathode separator 4, and the holding member 2, and a sealing member 5b is interposed between the anode separator 3 and the cathode separator 4 which are adjacent to each other.
In the anode separator 3, a fuel gas passage 6 is formed which faces an anode electrode 1a of the membrane-electrode assembly 1. In the cathode separator 4, an oxidant gas passage 7 is formed which faces a cathode electrode 1b of the membrane-electrode assembly 1. In addition, a cooling medium channel 8 is formed between the anode separator 3 and the cathode separator 4 which are adjacent to each other.